Systems and methods for built in test equipment for a brake control system

ABSTRACT

A method is disclosed that comprises severing an I/O channel between an EMAC and an aircraft component; sending a test signal to the brake system controller; receiving, from the brake system controller, a feedback signal to the test signal; and determining an appropriateness of the feedback signal.

TECHNICAL FIELD

The present invention relates to systems and methods for testing brakecontrol systems.

BACKGROUND

Modern aircraft braking systems often provide greater control,reliability and flexibility than systems of previous generations.However, to ensure optimum operation, the various components of modernbraking systems should undergo regular testing. In this regard, regulartesting may detect the need to replace wear items, identify componentswith the potential for malfunction, and identify potential areas forrecalibration.

Conventional testing of an aircraft brake system involves taking theaircraft out of service and either physically inspecting componentsand/or using the brake system while the aircraft remains grounded andparked. Such methods necessitate the loss of use of the aircraft duringtesting, while involving the labor and cost of technicians that detectpotential issues.

Accordingly, there exists a need for testing systems and methods thatallow for real time brake system testing.

SUMMARY

In various embodiments, a method is provided establishing a safetyinterlock between an electromechanical actuator controller (“EMAC”) andan aircraft component, severing an in/out (“I/O”) channel between theEMAC and the aircraft component, sending a test signal to the EMAC,receiving from the EMAC a feedback signal to the test signal, anddetermining an appropriateness of the feedback signal.

In various embodiments, a method is provided comprising disposing aselectively severable I/O channel between an electromechanical actuatorcontroller (“EMAC”) and an aircraft component, coupling the EMAC with abuilt in test equipment (“BITE”) region, wherein the BITE regioncomprises a testing module capable of sending a test signal to the EMAC,and establishing a safety interlock region by disposing a non-severableI/O channel between the EMAC and the aircraft component.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a brake control system and a BITE region inaccordance with various embodiments;

FIG. 2 illustrates an additional aspect of a brake control system and aBITE region in accordance with various embodiments;

FIG. 3 illustrates a more detailed view of a brake control system and aBITE region in accordance with various embodiments;

FIG. 4 illustrates a use scenario of a brake control system and a BITEregion in accordance with various embodiments;

FIG. 5 illustrates use of a brake control system and a BITE region inaccordance with various embodiments;

FIG. 6 illustrates a properly functioning ram position response in thetop graph and a malfunctioning valve response in the bottom graph inaccordance with various embodiments;

FIG. 7 illustrates a brake control system and a BITE region inaccordance with various embodiments; and

FIG. 8 illustrates a brake control system and a BITE region inaccordance with various embodiments having an integrated brake systemcontroller (“BSC”) and EMAC.

DETAILED DESCRIPTION

The detailed description of exemplary embodiments herein makes referenceto the accompanying drawings, which show exemplary embodiments by way ofillustration and its best mode. While these exemplary embodiments aredescribed in sufficient detail to enable those skilled in the art topractice the invention, it should be understood that other embodimentsmay be realized and that logical, electrical and mechanical changes maybe made without departing from the spirit and scope of the invention.Thus, the detailed description herein is presented for purposes ofillustration only and not of limitation. For example, the steps recitedin any of the method or process descriptions may be executed in anyorder and are not necessarily limited to the order presented. Moreover,many of the functions or steps may be outsourced to or performed by oneor more third parties. Furthermore, any reference to singular includesplural embodiments, and any reference to more than one component or stepmay include a singular embodiment or step. Also, any reference toattached, fixed, connected or the like may include permanent, removable,temporary, partial, full and/or any other possible attachment option.Additionally, any reference to without contact (or similar phrases) mayalso include reduced contact or minimal contact.

Systems and methods are disclosed herein that provide for testing abrake control system. In accordance with various embodiments, by testinga brake control system, the brake control system may be calibratedappropriately and/or potential areas of concern may be revealed. Thesystems and methods disclosed herein are suitable for use with variousaircraft braking systems, although there may be utility for use withother braking systems.

During conventional testing of an aircraft brake system, an aircraft istypically taken out of service and either physically inspected or thebrake control system is tested while the aircraft remains grounded andparked. However, as noted above, such methods necessitate the loss ofuse of the aircraft during testing, while involving the labor and costassociated with technicians to detect potential issues.

However, as it has been presently found by the present inventor, a brakecontrol system may be wrapped in (or encompassed by) a BITE system forin-use testing of the brake control system. In various embodiments, theBITE system may control I/O channels to various components of the brakecontrol system and may sever/reestablish those channels so that testingmay occur in real time, and often, without the need (or minimal need) totake an aircraft out of service. Accordingly, by using a BITE system, anaircraft brake control system may be appropriately maintained withoutexcess down time.

Moreover, in accordance with various embodiments, it has been found thatin electric brake systems, the BITE system may include a safetyinterlock surrounding an electromechanical actuator controller (“EMAC”).In that regard, the BITE system may test various brake functions withoutthe need to burden a BSC with handling built in testing, which tends toreduce processor load on the BSC, among other benefits. In variousembodiments, the BITE system retains emergency braking functionality andmay interrupt or terminate built in testing procedures in response to acommand from an emergency braking system.

Systems and methods disclosed herein may be useful for brake disk stacksfor use in aircraft. Aircraft may comprise one or more types of aircraftwheel and brake assemblies. For example, an aircraft wheel and brakeassembly may comprise a non-rotatable wheel support, a wheel mounted tothe wheel support for rotation, and a brake disk stack (also referred toas a brake assembly). An aircraft brake disk stack generally comprises afriction brake mechanism including a pressure plate that is adjacent toa means, device or other mechanism for exerting force such as ahydraulic piston motor or one or more electromechanical actuators. Forcemay be exerted through, for example, one or more rams. As referred toherein, “electric brake systems” employ one or more electromechanicalactuators to drive the one or more rams.

An aircraft brake typically further comprises an end plate distal fromthe means for exerting force and a plurality of interleaved rotor disksand stator disks which together form the brake heat sink. Each rotordisk may be coupled to the wheel for rotation therewith and each statordisk is coupled to the wheel support against rotation. The frictionbrake mechanism also generally includes a torque tube and a back leg onwhich a pressure plate, end plate and stator disks are slidably mountedagainst rotation relative to the wheel and rotor disks. The stator disksmay comprise two wear faces and the pressure plate may comprise a singlewear face. The rotors disks and stator disks may be formed of a frictionmaterial, such a carbon/carbon or a carbon metallic matrix material. Abrake head may house the piston motor or one or more rams that extend tomove the pressure plate and axially compress the brake disk stackagainst the end plate.

The actuator rams may be electrically operated actuator rams orhydraulically operated actuator rams, although some brakes may usepneumatically operated actuator rams. In electric brake systems, a BSCis coupled to one or more EMACs for a brake, which drives one or moreelectromechanical brake actuators. The BSC may be in communication witha brake pedal, and thus may control the EMACs in accordance withpilot/copilot braking commands.

With reference to FIG. 1, aircraft braking control system 100 includesat least one BSC 106, and frequently, at least two brake systemcontrollers may be used for redundancy purposes. BSC 106 may containvarious information pertaining to an aircraft, such as weight, make,model, and aircraft brake system configuration to assist in making thisdetermination. BSC 106 is in communication with various components thatrelay pilot input 102 to BSC 106. For example, pilot input 102 maycomprise a signal produced by one or more aircraft brake indicators. Inaddition to pilot input 102, input from other aircraft systems (notshown) may be relayed to BSC 106.

In this regard, an aircraft brake indicator may be any device thatallows a pilot to input braking commands. For example, an aircraft brakeindicator may be one or more aircraft brake pedals.

BSC 106 may provide an input/output interface (“I/O interface”) to othercomponents of an aircraft braking system. An I/O interface may compriseone or more I/O channels. For example, BSC 106 may be in communication(e.g., electrical communication) with components in a cockpit of theaircraft (e.g., an aircraft brake pedal) and/or other portions of anaircraft braking system (e.g., electromechanical actuator controller108). Such communication may be provided by, for example, the I/Ointerface (implemented using, for example, a bus or a network). Signalsfrom a brake pedal (e.g., in response to pilot input 102) may bereceived by the BSC 106 via one or more I/O channels. An I/O channel maybe any means of electrical communication. For example, an I/O channelmay comprise a wire connection or a wireless connection (e.g., via an RFtransceiver). An I/O channel may be severed transiently by interruptingan electrical connection, for example, by canceling the interruption.Accordingly, the severing of an I/O channel may be a reversible process.One or more I/O channels of an I/O interface may be reversibly severedat a given time.

In addition, BSC 106 may contain a computing device (e.g., a processor)and an associated memory. The associated memory may contain executablecode for performing braking control. The associated memory may comprisean article of manufacture including a computer-readable medium havinginstructions stored thereon that, if executed by a computing device(e.g., a processor), cause the computing device to perform variousmethods.

As noted above, in an embodiment and with reference to FIG. 1, a BSC maybe in communication with one or more EMACs. For example, BSC 106 may bein communication with EMAC 108. An EMAC, such as EMAC 108, may contain acomputing device (e.g., a processor) and an associated memory. Theassociated memory may comprise an article of manufacture including acomputer-readable medium having instructions stored thereon that, ifexecuted by a computing device (e.g., a processor), cause the computingdevice to perform various methods. The associated memory may containexecutable code for converting braking commands into a motor currentcommand.

An EMAC, such as electromechanical actuator controller 108, may providea drive signal to one or more electromechanical actuators (e.g.,electromechanical actuator 110, also referred to as “EA” 110) of anaircraft brake to drive an electromechanical actuator to a commandedposition. Thus, electromechanical actuator 110 may apply braking forcedirectly.

In various embodiments, EMAC 108 may communicate with EA 110 by sendinga command signal to EA 110 via an I/O interface. The command signal maycontain one or more commands and/or a drive signal/drive voltage. Forexample, a drive signal may command a certain amount of force to beapplied by EA 110.

In various embodiments, feedback 116 may be generated byelectromechanical actuator 110 and by electromechanical actuatorcontroller 108.

A BITE system (also referred to herein as a BITE region) may be anysystem that allows any portion of a brake control system (e.g., EMAC) tobe at least partially and reversibly disconnected from another aircraftsystem or component. With reference again to FIG. 1, BITE region 114 isshown with BITE components 112. A BITE system may allow for the severingand reestablishing of I/O channels or an I/O interface. A BITE systemmay comprise one or more switches, connectors, gateways, or otherdevices that allow for the selective, reversible severing of an I/Ochannel. For example, BITE components 112 allow for the selective,reversible severing of an I/O channel.

A BITE system may further comprise a testing module. A testing modulemay contain a computing device (e.g., a processor) and an associatedmemory. The associated memory may contain executable code for performingvarious actions, including the sending and receiving of test signals andthe creation and execution of test scripts. The associated memory maycomprise an article of manufacture including a computer-readable mediumhaving instructions stored thereon that, if executed by a computingdevice (e.g., a processor), cause the computing device to performvarious methods. In various embodiments, a brake system controller maycomprise a testing module and, in such embodiments, the BITE system neednot necessarily comprise a testing module.

In various embodiments, a testing module may be configured to send andreceive test signals. A test signal may be any signal that encodes acommand for an action performed for testing, calibration, optimizing, orother purposes that are not, at the time the testing signal is sent,needed for the immediate operation of an aircraft. In this regard, atest signal may command an aircraft component to perform a task. Forexample, a test signal may command an electromechanical actuator toactuate and/or may command a servo valve to perform a task. In variousembodiments, two or more test signals may be arranged in a particularorder to comprise a test script.

In various embodiments, a testing module may also be configured toreceive feedback (also referred to herein as a feedback signal or outputsignal) from an aircraft component and/or brake system controller and/orEMAC. Feedback may be delivered electronically, for example. Feedbackmay comprise any information relating to an aircraft component, such asits history, current status, or intended future status. Feedback may besent to a testing module or, with reference to FIG. 1, to BSC 106 orEMAC 108, for example, in response to a test signal.

Feedback may be used to calibrate, tune, optimize, or otherwise alterthe performance of various aircraft components. For example, feedbackmay comprise the actual pressure applied at an actuator. Feedback mayalso be used to detect when a component may require maintenance or acorrective action such as a repair. Feedback may also comprise a signalthat encodes a component failure.

A testing module or other BITE system component may receive feedback todetermine the appropriateness of the feedback. Appropriateness, as usedherein, includes determining if feedback is consistent with a set ofpredetermined, “expected” feedback values. As feedback may represent areal-world event, result or condition, it may be useful to determine ifthe feedback result comports with the expected event, result orcondition. Feedback that does not comport with the expected event,result or condition may be labeled as a failure, while feedback thatdoes comport with the expected event, result or condition may be labeledas a pass.

For example, if a test signal commanded a braking pressure of, forexample, 100 lbs/in² within a 3 lbs/in² tolerance and a feedback signalindicated that only 50 lbs/in² was actually applied, the testing moduleor other BITE system component may determine that the feedback isinconsistent with the “expected” value of the feedback. The testingmodule or other BITE system component may then report this inconsistency(i.e., failure) to other aircraft components, such as a cockpitcomponent. Alternatively, using the same situation, if a feedback signalreturned a value of 99 lbs/in², then the testing module or other BITEsystem component may determine that the feedback was appropriate and mayrecord this in a log.

In various embodiments, a testing module or EMAC 108 may send a testsignal to an aircraft component (e.g., an actuator), the aircraftcomponent may take an action based upon the test signal, and feedbackmay be sent to the testing module or EMAC or BSC for analysis.

For example, a testing module or EMAC 108 may send a test signal todrive EA 110 to a commanded position. Data collected during testing mayinclude phase lag (lag from command to response), step response (e.g.,0% commanded to x % commanded), and final position. These data may beused to determine the functional status of EA 110. For example, thefinal position may be recorded and performance may be compared to one ormore of the following: 1) known test cases (i.e., experimentally deriveddata), 2) predicted envelopes based on envelopes of operation, 3) trendsbased on past performance, and 4) performance compared to “peer”electromechanical actuators within the same aircraft (i.e., other EAs).

In further embodiments, a testing module or BSC 106 or EMAC 108 may senda test signal simulating a sensor failure. For example, BSC 106 mayreceive a signal indicating a brake pressure of 1000 psi when there isno input command for braking, thus indicating an uncommanded brakingfailure. BSC 106, if functioning as designed, should identify theuncommanded braking failure and respond accordingly.

With reference to FIG. 7, aircraft braking control system 700 isillustrated. Brake input 702 may be received by BSC 704. BSC 704 maydetermine an appropriate braking response to the brake input 702 andforward such commands to EMAC 710. EMAC 710 may in turn provide a drivesignal or other command signal to EA 714, which is one of severalelectromechanical actuators on electric brake 716. Testing module 706may be in electrical communication with EMAC 710. Safety interlock 708may be disposed around EMAC 710, allowing one or more I/O channels toEMAC 710 to be selectively severed and re-established. In that regard,I/O channels from BSC 704 to EMAC 710 may be selectively severed andre-established. During a test, safety interlock 708 may sever I/Ochannels from BSC 704 to EMAC 710 and testing module 706 may injecttesting commands to EMAC 710. EMAC 710 may respond to those commands,for example, by sending a command signal and/or drive signal to EA 714.

Emergency brake system 712 may comprise any system configured to relayemergency braking commands. An emergency braking command may be anycommand that requests braking without regard to BITE status. In otherwords, an emergency braking command requests the cessation of testingand the application of braking force. Emergency brake system 712 maycomprise one or more emergency brake input devices (e.g., pedal,handles, switches, button, etc). The emergency brake system 712 may alsocomprise an I/O channel that connects BSC 704 to EMAC 710 through achannel that is not able to be severed by safety interlock 708.Emergency brake system 712 may be in electrical communication with EMAC710 in a manner that bypasses safety interlock 708.

In response to an emergency braking command from emergency brake system712, EMAC 710 may cease testing that may be in progress and may issue abraking command to EA 714 in accordance with the emergency brakingcommand.

In various embodiments, emergency brake system 712 may receive anindication from an aircraft component that is indicative of wheeltouchdown upon landing. For example, a landing gear WOW(“weight-on-wheel”) signal, landing gear downlock signal, TQA (“ThrottleQuadrant Assembly”) signal, throttle position signals, a signalindicating that wheel speed is accelerating at a rate consistent withtouchdown, and the like may be sent by emergency brake system 712 toEMAC 710. In that regard, EMAC 710 may cease testing and safetyinterlock 708 may restore I/O channels.

Now referring to FIG. 2, BITE system 200 is illustrated. BITE region 206is shown wrapping EMAC 202. I/O channels 208 and 210 are shown enteringBITE region 206 and connecting to EMAC 202. BITE region 206 mayreversibly sever I/O channels 210 and 208. While severed, BITE region206 may (through, for example a testing module) send test signalsthrough I/O channels 210 and 208 to EMAC 202.

In certain situations, for safety, it is desirable to ensure thattesting may be interrupted by external factors (e.g., pilot input). Forexample, there may be situations where a pilot may need to unexpectedlycommand braking. If testing is in progress and such a situation arises,it is advantageous to have a system by which testing could beinterrupted and the brake control system could return to pilot control.In various embodiments, safety interlock 204 allows EMAC 202 tocommunicate with other aircraft components. For example, safetyinterlock 204 may communicate directly with emergency aircraft signals,without intervention of BITE region 206. Thus, safety interlock 204 maycomprise I/O channels between aircraft components that BITE region 206may not sever, thus providing uninterruptible I/O channels. In suchembodiments, safety interlock 204 may thus comprise I/O channels thatare redundant with respect to the severable I/O channels of BITE region206. In various embodiments, such redundancy enhances safety and ensuresthat signals, such as emergency signals, have an alternate pathway thatbypasses BITE region 206. In various embodiments, BITE region 206 maydetect the use of safety interlock 204 and thus determine that anytesting may be ceased. Accordingly, BITE region 206 may reestablish oneor more severed I/O channels responsive to the use of safety interlock204.

In various embodiments, with reference to FIG. 1, BSC 106 and EMAC 108may agree that present conditions are suitable to commence testing. Forexample, EMAC 108 may communicate with BSC 106 to determine if it isappropriate to begin testing. In addition, BSC 106 may command EMAC 108to commence testing.

Safety interlock 204 may also detect signals from other aircraftcomponents and detect patterns indicative of a scenario where testingmay cease. For example, if a pilot depresses a brake pedal during flightand aircraft altitude is dropping, the safety interlock 204 may notifythe BITE region 206 to reestablish I/O channels and cease testing.

In various embodiments, BITE region 206 may determine that one or moretests may be performed. For example, tests may be programmed to occurover varying time intervals. Testing may be performed using test scriptsthat arrange several testing procedures into a particular order.

Prior to conducting a test, BITE region 206 (through, for example, atesting module), may determine if an aircraft's current state willaccept the request for the test of the aircraft's brake control system.For example, a BITE system may determine if the aircraft is parked,taxiing, taking off, flying, landing, or on approach for landing. Incertain instances, the BITE system may determine that testing should notoccur.

If it is appropriate to run a test, BITE region 206 may then reversiblysever one or more I/O channels (e.g., I/O channels 210 and 208) toprepare for testing. Testing may comprise generating and sending testsignals. For example, test signals may comprise signals encodingcommands typically associated with parking, taxiing, taking off, flying,landing, or on approaching for landing. In various embodiments, testsignals may also encode various data related to aircraft status. Forexample, test signals may comprise wheel speed signals, landing gear WOWsignals, landing gear downlock signals, TQA signals, throttle positionsignals, and the like.

In various embodiments, a testing may occur when the aircraft is parked.In that regard, one or more EAs on a wheel may be commanded to applypressure sufficient to keep the aircraft parked, while the remaining EAsundergo testing. Upon completion of the testing, the one or more EAsthat underwent testing may be commanded to apply pressure sufficient tokeep the aircraft parked and the one or more EAs that had been applyingparking pressure may undergo testing. Testing may continue in this“round robin” format until all EAs on a wheel have been tested. In thatregard, parking functionality is maintained while testing occurs.

Moreover, for aircraft with multiple wheel bogie gears, the “roundrobin” can be performed on a brake-by-brake scheme (a “round robin” ofbrakes). For example, on a 4-wheel bogie gear with brakes 1-4, brake 1may be tested while brakes 2-4 are increased in pressure to assure theaircraft does not move. Then, brake 2 may be tested while pressure isincreased at brakes 1, 3 and 4 to maintain the aircraft in park. Testingmay proceed until all brakes are tested.

In various embodiments, and as described herein, BITE region 206 maythen receive feedback. Feedback may be used to compare and evaluateactual system responses to expected responses. BITE region 206 may thenrecord, communicate and/or summarize the results of the test.

With reference to FIG. 3, brake control system 300 is shown. The brakecontrol system comprises an EMAC 110, labeled as processor 310. Thebrake control system also comprises sensor and inputs 304 and signalconditioning circuits 308, each of which is in electrical communicationwith BITE system 306. The brake control system further comprises signalconditioning circuits 312 and actuator outputs 314, each of which is inelectrical communication with BITE system 306. Safety interlock 302 isin electrical communication with sensor and inputs 304 and, as shown,this connection is not made via BITE 306.

As shown in FIG. 3, BITE system 306 is in communication with variousbrake control system components (e.g., signal conditioning circuits 308)and may, accordingly, selectively sever or reestablish I/O channels of abrake control system. The BITE system may selectively sever orreestablish I/O channels directly to or from an EMAC, as shown in theinteraction between BITE 306 and EMAC 310, or the BITE system mayselectively sever or reestablish I/O channels of other brake controlsystem components, as shown in the interaction between BITE 306 andsensor and inputs 304. Also as shown, safety interlock 302 may bypassBITE 306 so that operation of BITE 306 may be modified should safetyreasons so require.

For example, when it is determined that running a test is appropriate, aBITE system may sever I/O channels and a test script may be executed.The test script may comprise test signals that command taxi stops, sothe brake control system would function as if the aircraft were in ataxi maneuver on a runway. The test script may then indicate that thethrottles are moved forward for takeoff power and that the wheel speedhas increased, simulating a takeoff. The test script may furthercomprise a test signal encoding a weight on wheels signal that reportsthat the wheels have left the ground, further simulating takeoff.Further, a test signal may indicate that the landing gear has beenretracted. A test signal may indicate that the aircraft flaps have beenlowered and that the throttles have been set to idle, indicating animminent landing. In response, the brakes may be applied. The aircraft'sresponses to these events may be recorded and evaluated to determineabnormalities or other areas of concern.

An example of BITE operation 400 is shown in FIG. 4. EMAC Input 402 isforwarded to BITE Enabled decision point 404. If BITE is enabled, it isunderstood that EMAC Input 402 is a simulation per BITE simulation point406. Accordingly, in a simulation, EMAC Input 402 comprises a testsignal. If BITE is not enabled, EMAC Input may proceed to the brakecontrol system 408. Within brake control system 408, EMAC hardware andsoftware 410 process the EMAC Input 402 and determine an appropriateresponse. BITE monitoring and evaluation 412 monitors EMAC hardware andsoftware 410 and EMAC Input 402 when BITE is enabled.

EMAC hardware and software 410 may prepare a signal responsive to EMACInput 402. Such a signal may be passed to BITE Enabled decision point414. If BITE is not enabled, the signal may be forwarded to anotheraircraft component as EMAC output 418. If BITE is enabled, BITE mayintervene at BITE Test Signal Intervention 416 to monitor and/or alterthe output signal. The output of BITE Test Signal Intervention 416 isEMAC output 418.

With reference to FIG. 5, BITE operation example 500 is shown. I/Ochannel 502 exists between an aircraft component and tested component508. I/O channel 512 exists between tested component 508 and an aircraftcomponent, which may or may not be the same aircraft component involvedwith I/O channel 502. I/O channel 502 may be selectively severed atpoint 504 while I/O channel 512 may be selectively severed at point 514.Points 504 and 514 may provide access to a BITE region (not shown)comprising one or more BITE components. As described above, various BITEcomponents may generate test signals, receive feedback signals, andevaluate feedback signals.

During testing, I/O channel 502 may be selectively severed at point 504.The BITE region may introduce test signal 506 at point 504. Test signal506 is relayed to tested component 508. Tested component 508 may thenrespond to test signal 506 and produce feedback signal 510. Feedbacksignal 510 may be routed to the BITE region at point 514. The BITEregion may then record feedback signal 510 and evaluate it accordingly.

Evaluation of feedback signals may be performed in any suitable manner,as elsewhere described herein. For example, FIG. 6 depicts testevaluation 600. Test evaluation 600 comprises a comparison of a properlyfunctioning ram position response (top graph) and a malfunctioning ramposition response (bottom graph). One or more properly functioning ramposition response profiles may be stored in a BITE region's memory forcomparisons to future testing. The stored properly functioning ramposition response profiles may be derived from experimental data or maycomprise previous “known good” results of the same testedelectromechanical actuator. In FIG. 6, an EMAC may command an EA to movea ram to a predetermined position. The movement of the ram may beconsidered the response.

With continued reference to the top graph of FIG. 6, a properlyfunctioning ram position response is shown. Time is shown on the x axiswhile response is shown on the y axis. Response may be determined byfeedback signals. The command box 606 illustrates the commanded time andcommanded position. For demonstration purposes, response is depicted asa generic indicator for the action of a tested component, although, invarious embodiments, response could represent, for example, appliedbrake force.

Lag 602 illustrates the lag time between test signal transmission andthe beginning of a response. Overshoot 604 illustrates the differencebetween the commanded response and the response produced. In variousembodiments, an overshoot and/or a lag within a certain range isconsidered acceptable.

With reference now to the bottom graph of FIG. 6, a malfunctioning ramposition response is shown. Time is again shown on the x axis whileresponse is again shown on the y axis.

Lag 608 illustrates the lag time between test signal transmission andthe beginning of a response. As shown, lag 608 is larger than lag 602,which may indicate a problem with the tested component. Overshoot 610illustrates the difference between the commanded response and theresponse produced. As shown, overshoot 610 is greater than overshoot604. The BITE region may then determine that a malfunction is occurring.Point 612 illustrates an aberration in the response. In a test of anelectromechanical actuator, such an aberration may indicate a mechanicalissue involving the electromechanical actuator. The BITE region may usethis information to determine that a malfunction is occurring and,moreover, to identify the type of malfunctioning occurring.

More specifically, there are a number of tests contemplated herein. Forexample, force, position and motor current may be manipulated fortesting purposes. The velocity and acceleration in both linear andangular modes may be measured in testing. For example, an EMAC may becommanded to send drive power to an EA. The output of the EMA (i.e., thevolt/current waveform) may be observed and compared to a standard orexpected test result.

In additional testing modes, an EA's deadband (i.e., time to getstarted), rise time to a position, force or motor current, etc. can beanalyzed to assure proper functioning. Tests may occur in closed loopcontrol or open loop control.

Test command inputs may include EMAC-to-EMAC communications (i.e.,commands and responses) may be tested, as well as EA to EMACcommunications (commands and responses). System voltage, system current,motor voltage, motor current, position: angular and linear (angular onthe motor or linear from a different EMA linear sensor), velocity(angular and linear), acceleration (angular and linear), EMA force. Testcommand outputs may include EMAC commands and responses, motor drivevoltage, motor drive current, motor angular position, velocity, andacceleration.

As described above, the use of a safety interlock surrounding an EMACmay provide improved efficiencies in testing while maintaining emergencybraking functionality. In various embodiments, a BSC and an EMAC may beintegrated as a single unit. In such configurations, a safety interlockmay be disposed around the integrated BSC/EMAC.

With reference to FIG. 8, brake system 800 is illustrated. Brake input802 may be received by integrated BSC 808 and EMAC 810. Thoughintegrated, functionally integrated BSC 808 and EMAC 810 is illustratedas BSC 808 and EMAC 810, even though both BSC 808 and EMAC 810 areconfigured as an integrated unit. BSC 808 may determine an appropriatebraking response to the brake input 802 and forward such commands toEMAC 810. EMAC 810 may in turn provide a drive signal or other commandsignal to EA 816, which is one of several electromechanical actuators onelectric brake 814. Testing module 804 may be in electricalcommunication with EMAC 810. Safety interlock 806 may be disposed aroundintegrated BSC 808 and EMAC 810, allowing one or more I/O channels tointegrated BSC 808 and EMAC 810 to be selectively severed andre-established. In that regard, I/O channels from brake input 802 may beselectively severed and re-established. During a test, safety interlock806 may sever I/O channels from brake input 802 to integrated BSC 808and EMAC 810 and testing module 804 may inject testing commands tointegrated BSC 808 and EMAC 810. Integrated BSC 808 and EMAC 810 mayrespond to those commands, for example, by sending a command signaland/or drive signal to EA 816.

Emergency brake system 812 may comprise any system configured to relayemergency braking commands. Emergency brake system 812 may be inelectrical communication with EMAC 810 in a manner that bypasses safetyinterlock 806.

In response to an emergency braking command from emergency brake system812, EMAC 810 may cease testing that may be in progress and may issue abraking command to EA 816 in accordance with the emergency brakingcommand.

In various embodiments, emergency brake system 812 may receive anindication from an aircraft component that is indicative of wheeltouchdown upon landing. For example, a WOW signal or a signal indicatingthat wheel speed is accelerating at a rate consistent with touchdown maybe sent by emergency brake system 812 to EMAC 810. In that regard, EMAC810 may cease testing and safety interlock 806 may restore I/O channels.

Benefits, other advantages, and solutions to problems have beendescribed herein with regard to specific embodiments. Furthermore, theconnecting lines shown in the various figures contained herein areintended to represent exemplary functional relationships and/or physicalcouplings between the various elements. It should be noted that manyalternative or additional functional relationships or physicalconnections may be present in a practical system. However, the benefits,advantages, solutions to problems, and any elements that may cause anybenefit, advantage, or solution to occur or become more pronounced arenot to be construed as critical, required, or essential features orelements of embodiments encompassed by this disclosure. The scope of theclaimed matter in the disclosure is accordingly to be limited by nothingother than the appended claims, in which reference to an element in thesingular is not intended to mean “one and only one” unless explicitly sostated, but rather “one or more.” Moreover, where a phrase similar to“at least one of A, B, or C” is used in the claims, it is intended thatthe phrase be interpreted to mean that A alone may be present in anembodiment, B alone may be present in an embodiment, C alone may bepresent in an embodiment, or that any combination of the elements A, Band C may be present in a single embodiment; for example, A and B, A andC, B and C, or A and B and C.

Systems, methods and apparatus are provided herein. In the detaileddescription herein, references to “various embodiments”, “oneembodiment”, “an embodiment”, “an example embodiment”, etc., indicatethat the embodiment described may include a particular feature,structure, or characteristic, but every embodiment may not necessarilyinclude the particular feature, structure, or characteristic. Moreover,such phrases are not necessarily referring to the same embodiment.Further, when a particular feature, structure, or characteristic isdescribed in connection with an embodiment, it is submitted that it iswithin the knowledge of one skilled in the art to affect such feature,structure, or characteristic in connection with other embodimentswhether or not explicitly described. After reading the description, itwill be apparent to one skilled in the relevant art(s) how to implementthe disclosure in alternative embodiments.

Furthermore, no element, component, or method step in the presentdisclosure is intended to be dedicated to the public regardless ofwhether the element, component, or method step is explicitly recited inthe claims. No claim element herein is to be construed under theprovisions of 35 U.S.C. §112(f), unless the element is expressly recitedusing the phrase “means for.” As used herein, the terms “comprises”,comprising”, or any other variation thereof, are intended to cover anon-exclusive inclusion, such that a process, method, article, orapparatus that comprises a list of elements does not include only thoseelements but may include other elements not expressly listed or inherentto such process, method, article, or apparatus.

1. A method comprising: establishing a safety interlock between anelectromechanical actuator controller (“EMAC”) and an aircraftcomponent; severing an I/O channel between the EMAC and the aircraftcomponent; sending at least one test signal to the EMAC; receiving, fromthe EMAC, a feedback signal to the test signal; and determining anappropriateness of the feedback signal.
 2. The method of claim 1,further comprising reestablishing the I/O channel.
 3. The method ofclaim 1, wherein the feedback signal relates to a least one of anelectromechanical actuator and a servo.
 4. The method of claim 1,wherein the test signal commands an electromechanical actuator toactuate.
 5. The method of claim 1, further comprising generating a testscript comprising a plurality of test signals with a testing module. 6.The method of claim 1, further comprising establishing a non-severableI/O channel between the EMAC and an emergency braking system.
 7. Amethod comprising: disposing a selectively severable I/O channel betweenan electromechanical actuator controller (“EMAC”) and an aircraftcomponent; coupling the EMAC with a BITE region, wherein the BITE regioncomprises a testing module capable of sending a test signal to the EMAC;and establishing a safety interlock region by disposing a non-severableI/O channel between the EMAC and the aircraft component.
 8. The methodof claim 7, further comprising placing the safety interlock region inelectrical communication with the testing module.
 9. The method of claim8, further comprising loading a test script into the testing module. 10.The method of claim 9, further comprising loading an expected resultprofile into the testing module.
 11. The method of claim 7, furthercomprising placing the BITE region in electrical communication with asignal conditioning circuit.
 12. The method of claim 7, furthercomprising placing the BITE region in electrical communication with asensor.
 13. The method of claim 7, further comprising placing the EMACin electrical communication with an emergency braking system.
 14. Themethod of claim 13, receiving, at the EMAC, an emergency braking commandfrom the emergency braking system.
 15. The method of claim 14, furthercomprising stopping, by the EMAC, of a test in response to the emergencybraking command.